Springer’s LaTeX search service (example results) allow searching for LaTeX strings or finding the LaTeX equations in an article. Since LaTeX is used to markup equations in many scientific publications this could be an interesting way to find related work or view an equation-centric summary of a paper.
You can provide a LaTeX string, and Springer says that besides exact matches they can return similar LaTeX strings:
Or, you can search by DOI or title to get all the equations in a given publication:
Under each equation in the search results you can click “show LaTeX code”:
Right now it just searches Springer’s publications; Springer would like to add open access databases and preprint servers. Coverage even in Springer journals seems spotty: I couldn’t find two particular discrete math articles papers, so I’ve written Springer for clarification. As far as I can tell, there’s no way to get from SpringerLink to this LaTeX search yet: it’s a shame, because “show all equations in this article” would be useful, even with the proviso that only LaTeX equations were shown.
A nice touch is their sandbox where you can test LaTeX code, with a LaTeX dictionary conveniently below.